Drilling machine



G. H. GILMAN DRILLING MACHINE Dec. 24, 1929.

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Dec. 24, 1929. G. H. GlLMAN 1,740,813 DRILLING MACHINE original Filed July 24. 1922 2 Smells-She@JL 2 77 'e 9 ,//ffl C yy; f5 //f//Q/ f Ira/vena?.- (eoegel. @wiwi/Lan. El] m1 @MXL W (Hays.

Patented Dec. 24, 1929 PATENT OFFECE GEORGE H. GILMAN, OF BELMONT, MASSACHUSETTS DRILLING MACHINE Application filed July 24, 1922, Serial No. 577,010. Renewed May 8, 1929.

My invention relates to drilling machines side of the head of the piston by way of and particularly but not exclusively to that type wherein the drilling tool is operated both by impact and rotation.

5 My invention, however, will be best understood from the following description when read in the light of the accompanying drawings of a specific embodiment of my invention selected for illustrative purposes, while thescope of my invention will be more particularly pointed out in the appended claims.

In the drawings Fig. 1 shows a longitudinal section of a rock drill constructed according to my invention;

Figs. Q, 3 and t respectively are sections on the lines 2-2, 3-3 and 4-4 of Fig. 1;

and

Fig. 5 is a section on the line 5 5 of Fig. 3.

Referring to the drawings, which show the embodiment of my invention selected for illustrative purposes, I have indicated a rock drill which is provided at its forward end with a chuck 1 which carries the drill steel 3,

the drill steel being` mounted in the chuck in such manner that rotation of the chuck causes the drill steel to rotate with it.

For imparting percussion to the drill steel I herein provide a piston which includes a head 5 and the forward and rearward reduced diameter portions 7 and 9, the portion 7 being arranged to strike the end of the drill steel at the end of the forward stroke of the piston.

sary to explain how the piston cooperates with my present invention.

The bore 11 which receives the reduced diameter portion 9 of the piston is provided adjacent its forward end with an annular groove 13 which is in constant communication by way of passages not shown with the source of motive fluid supply when the machine is in operation. Then the piston is in its position shown by Fig. 1 motive fluid 59 passesfrom said groove 13 to the rearward the passage formed by the reduced portion 15 of the reduced diameter portion 9 of the piston. As the forward side of the head 5 then uncovers the exhaust port 17 for said head, the hammer moves forwardly.

The groove 13 is in conhtant communication by way of passages not shown with the space 19 at the rear of the bore 11. Further, the bore 1l is provided with a port 2l in constant communication with a source of motive supply. Therefore, when the piston reaches the forward end of its travel motive fluid passes from the groove 13 and from the source of motive fluid supply by way of the space 19 and port 21 through the bore 11 into the passages 23 which lead to the forward end of the bore 25 receiving the head 5 of the piston. When this takes place the head 5 has opened the rearward end of the bore 25 to the atmosphere by way of the exhaust port 17 and consequently the motive fluid acting on the forward side of the head 5 forces the piston rearwardly against the pressure acting on the end of the rearward portion 9 of the piston.

For rotating the chuck I provide a motor, which motor in the submitted embodiment of my invention comprises a rotary fluid actuated member 27. 'Ihe member 27 on its periphery is herein provided with the vanes 29 or pistons which coact with the abutments 3l arranged at opposite sides of the motor. For causing the abutments to move I may gear them to the member 27 in an convenient manner and, as shown, for this purpose I provide the peripheries of the member 27 and the abutmcnts with intermeshing gear teeth 32. It will thus be seen that the motor illustrated is of the rotary type delivering continuous uni-directional rotary motion and comprising three gear toothed members, the central one of which in the submitted embodiment of my invention is a rotary piston member and the side ones, rotary abutments.

The annular gear member 27 is mounted on the exterior of that portion of the rock drill casing 35 which surrounds the reduced diameter portion 9 of the piston and as shown is located coaxially with the drill steel. The

end covers of the casing for the motor are provided by the forward side of the handle base 37 and the rearward face of the bearing blocks 39 while the peripheral portion of the casing is afforded by the member 41 bored out to receive the rotor and abutments. Motive fluid is led to the motor by means of intake passages 43 in communication with the space 19, while the exhaust from the motor is led to the atmosphere by way of passages 45. As the motor shown is generally of a known type, it is believed that it is unnecessary to further describe it.

For transmitting the motion of the motor to the chuck l herein provide a pair of shafts 47 which shafts .extend at opposite sides of the rock drill forwardly from the abutments 31, the shafts being supported in suitable bearings and being removably secured to the abutments by means of keys 49. As shown, the shafts are broached to form four such keys spaced in quarteriug relation while the abutments are provided with key ways for receiving the keys.

At its forward end each shaft carries a pair of aligned eccentrics 51 which as shown are integral with the shafts. The adjacent eccentrics on each shaft as shown are positioned with relation to each other angularly 180 degrees apart, while as shown the eccentric directly opposite any given eccentric has the same angular relation with reference to the shaft carrying the eccentric as the given eccentric has to its shaft, which is to say as shown the pairs of directly opposite eccentrics rotate in phase.

As illustrated, on the chuck is formed an annular series of ratchet teeth 53 while each eccentric carries a pawl 55 adapted to mesh with said ratchet teeth, each pawl being held in mesh by means of a separate flat leaf spring 57 of approximately the width of the pawl. For securing the springs in position each spring herein is provided with an arcuate terminal portion 59 which enters an annular enlargement in the perforation of the casing receiving the side bolts 61 of the machine. In this manner the side bolts hold the springs in position while the corner 62 of the spring bearing against the casing prevents turning of the terminal portion in its recess.

Vith the arrangement shown the pawls on opposite eccentrics act together and rotate the chuck an annular distance corresponding to the pitch of one of the ratchet teeth for each revolution of the shafts 47. As the eccentrics on each shaft are arranged 180O apart it will be noticed that the chuck will be moved for one revolution of the shafts 47 twice the distance which a single eccentric moves it. By pulling a shaft 47 out of the corresponding abutment 31 which as heretofore eX- plained may be readily done by reason of the keys 49 on the shafts slidably fitting the abutments, and turning the shaft before reinserting it, the angular relation between the eccentrics on the opposite shafts-may be varied and therefore the speed of the chuck relatively to that of the motor may be varied. rlhis may be also done by moving the gear members of the motor out of mesh and placing them again in mesh with a different angular relation between the parts. For example if by either of the ways mentioned, directly opposite eccentrics are placed 90O apart, the chuck will be moved for one revolution of the shafts four times the distance it is moved by one eccentric. Y

F or readily reducing the speed of rotation of the chuck relative to that of the motor in the present arrangement, I may withhold one pair of the pawls from meshing with the ratchet. For this purpose I herein provide the ring indicated in its entirety at 63 which ring is made in two parts for easy insertion and is rotatively mounted on the chuck just forward of the forward eccentrics 51. The portion G4 of the ring carries raised portions 65, while the forwardly located pawls 55 are providedwith lugs 67 of such length as to be in the path of the raised portion when the parts are in the position shown by F ig. 3.

For turning the ring 63 I have shown the portion 68 thereof provided with a handle V69 which extends through the slot formed through the chuck casing. vVhen the handle is moved to the end of the slot 70 opposite that atwhich it is shown by Fig. 3 the raised portions 65 will be moved out of the pat-h of the lugs 67 which will permit the pawls which carry said lugs to move into mesh with the ratchet teeth.

For holding the handle 69 at the ends of the slot 70 l have herein provided the handle with an elongated opening 71 into which eX- tends the spring 7 3 riveted to the handle at 75. rlhe spring adjacent its end is provided with a semi-spherical swelling 77 which is adapted to snap into semi-spherical recesses 79 in the sides of the slot. For preventing entrance of dirt into the slot 70 the handle carries a dust guard S1 sliding on the exterior surface of the casing, the dust guard being provided with an opening through which the handle extends and is secured to the handle by any suitable means, for example by welding. i

Although l have described for purposes of illustration one specific embodiment of my invention it is to be understood that l am not limited thereby to its particular mechanical details but that within the scope of my invention wide deviations may be made therefrom withoutv departing from the spirit of my invention.

Claims:

1. In a rock drill, the combination with a drill steel, a chuck for said steel, a hammer for operating said drill steel, and an independent rotary type motor for rotating said steel, of reduction gearing comprising a series of ratchet teeth carried by said chuck, a plurality of eccentrics angularly arranged relatively to each other and driven by said independent motor, pawls carried by said eccentrics and cooperating with said series of ratchet teeth, and means for changing the speed of rotation or" said chuck relatively to the speed of rotation of said motor comprising means for withholding one of said pawls from engagement with said series of ratchet teeth.

2. In a rock drill, a drill steel, a motor of the rotary type for rotating said steel, reduction gearing comprising a plurality of intermittent grip, devices` for successively transmitting the motion of said motor to said steel, and means for rendering one of said intermittent grip devices operative or inoperative at will for varying the speed of rotation of said steel. Y

3. In a rock drill, a drill steel, a chuck for said steel, a motor oi the rotary type for rotating said chuck, reduction gearing comprising a plurality of aligned eccentrics driven by said motor, said eccentrics being angularly arranged relatively to each other, intermittent grip devices connecting said eccentrics to said chuck for successively imparting portions of the motion of said motor to said chuck, and means for changing'the speed of rotation of said chuck relatively to the speed of rotation of said motor comprising means for rendering one of said intermittent grip devices inoperative.

4t. In a rock drill, a drill steel, a chuck for said drill steel, a motor of the rotary type for rotating said chuck, reduction gearing comprising a plurality of pairs of eccentrics driven by said motor, the eccentrics of each pair being located at opposite sides of said chuck and the eccentrics ot' said pairs on the same side of said chuck being angularly arranged relatively to each other, intermittent grip devices connecting the eccentrics to said chuck, said devices operating to cause part of the rotation of each eccentric to be imparted to said chuck, and means for changing the speed of rotation of said chuck relatively to the speed of said motor comprising mechanism for rendering said devices associated with one of said pairs of eccentrics inoperative.

5. In a rock drill, a drill steel, a chuck for said drill steel, a motor of the rotary type for rotating said chuck, reduction gearing comprising a plurality of pairs of eccentrics driven by said motor, the ecentrics of each pair rotating in phase and being located at opposite sides of said chuck and the eccentrics of said pairs on the same side of said chuck being angularly arranged relatively to each other, intermittent grip devices connecting the eccentrics to said chuck, said devices operating to cause part of the rotation of each eccentric to be imparted to said chuck, and means for changing the speed of rotation of said chuck relatively to the speed of said motor comprising mechanism for rendering said devices associated with one of said pairs of eccentrics inoperative.

6. In a rock drill, a drill steel, a chuck for said steel, a motor of the rotary type for rotating said chuck, reduction gearing comprising means for imparting the motion of said motor to said chuck, said means comprising a plurality7 of eccentrics and intermittent grip devices operated by t-he eccentrics and connected to said chuck, a driving connection between said motor and eccentrics, said driving connection permitting the angular relation of said eccentrics to be varied for varying the ratio of said reduction gearing.

7. In a rock drill, a drill steel, a chuck for said steel, a motor for rotating said chuck, reduction gearing comprising means for imparting the motion of said motor to said chuck, said means comprising a plurality of shafts each carrying an eccentric, intermittent grip devices connecting said eccentrics to said chuck, a driving connection between said motor and said shafts, said driving connection permitting the annular relation of said shafts to be changed for varying the ratio of said reduction gearing.

8. In a rock drill, a drill steel, a chuck for said drill steel, a fluid operated hammer piston for causing percussion to be imparted to said drill steel, a fluid operated motor delivering continuous uni-directional mot-ion, reduction gearing means comprising means for imparting portions of the motion of said motor to said drill steel, and means for varying the speed of rotation of said chuck relatively to the speed of said motor.

In testimony whereof, I have signed my name to this speciiication.

GEORGE H. GILMAN. 

